1. Field of the Invention
The present invention relates to a process for producing phenoxyalkene derivatives useful as agricultural chemicals.
2. Description of the Prior Art
It has been known that phenoxyalkene derivatives can be produced by reacting a phenol having the formula ##STR5## wherein R.sub.3 represents hydrogen atom or ##STR6## Y' and Z' are the same or different and respectively represent hydrogen atom, trifluoromethyl group, a halogen atom, or lower alkyl group, nitro group or cyano group, with a monohalogen compound having the formula ##STR7## wherein R.sub.4 represents a lower alkyl group; R.sub.5 represents carboxyl, hydroxymethyl, allyloxycarbonyl, a lower alkoxycarbonyl, a lower haloalkoxycarbonyl, a S-lower alkylthiocarboxyl, carbamoyl, a N-lower alkylcarbamoyl or a N-phenylcarbamoyl group in a solvent such as ketones e.g. acetone, and methylethyl ketone, ethers such as tetrahydrofuran, diethyl ether, methyl butyl ether, ethyleneglycol dimethyl ether; dimethylformamide, dimethylacetamide, dimethylsulfoxide, benzene, toluene and hexane, etc. in the presence of a dehydrogenhalide agent such as an alkali metal compound e.g. sodium or potassium compound or an alkaline earth metal compound e.g. calcium or magnesium compound.
However, a dehydrogenhalidation of the monohalogen compound is caused by this process. Thus, a large amount of the monohalogen compound should be used and a large amount of the by-products is produced to cause low yield of the object compound.
The inventors have studied to obtain a phenoxyalkene derivative having high purity in high yield. Thus, the special reaction mechanism of combination of an etherification and an unsaturated double bond formation in one step has been found.